Spikes, Willis clubbing it?

The 49ers top two tacklers — starting inside linebackers Patrick Willis and Takeo Spikes — are wearing club-like casts on their respective right hands, only they won’t say precisely why.

Both players got hurt in Sunday’s 41-20 win over Seattle, that much we know. Both players played in spite of the pain, that much has been said.

Both are expected to play Thursday at San Diego, according to defensive coordinator Greg Manusky today, but neither players knows how effective they will be playing, in essence, one-handed.

If it’s anything like Willis did wearing a club as a rookie, the 49ers will be just fine.

“He seemed to do pretty good with it,” Spikes said. “Actually, he did damn good with a cast on his hand. Might break the interception streak, that’s one of the things that you worry about. It means I have to practice snagging with one hand, the left hand.”

As a rookie, Willis played the second half of the season with a club on his broken right hand, just as he did one year in college. Spikes has never played with a club, but he did play without the proper use of one arm last season when he injured his pec muscle.

Where this becomes a problem Thursday is in pass coverage, at least in terms of holding onto any Philip Rivers passes. But, the club knocks down passes just the same, it just hurts.

“No, it’s never easy if you don’t have both your hands,” Willis said. That’s something that this game is about. You gotta be able to use your hands, but sometimes you gotta make do with what you got.”

Willis does not usually cover anyone, as it is. Spikes often shadows a running back or tight end. If he can’t be effective, the 49ers can replace him on passing downs with rookie NaVorro Bowman — but then, they’ll just end up remembering why Bowman got benched last month in the first place.

Whatever the case, Rivers will be playing close attention.

“I’ll tell you what,” Rivers said in a conference call. “Those guys have to be two of the better inside linebackers in the league. Obviously, Spikes has been playing for a long time. I remember him most in Buffalo.

“And then, Willis, in his short career has obviously established himself as one of the best in the game. They get probably grouped into the downhill linebackers — just inside run-game pluggers and all that, but they both run really well. They can play sideline to sideline. They both do a great job defending the pass. They’re complete players. I think that’s where it starts.”